How to Fix a Trailing Comma Error in JSON

4 min read · Updated 2026-07-15

A trailing comma is one of the most common reasons valid-looking JSON fails to parse. JSON is stricter than JavaScript object syntax: the final item in an object or array cannot be followed by a comma.

What the error looks like

The parser usually reports an unexpected token near a closing brace or bracket. The real problem is the comma immediately before it.

{
  "name": "YouKit",
  "private": true,
}

How to fix it

Remove the comma after the final property or array item, then validate the document again. Keep commas only between adjacent values.

{
  "name": "YouKit",
  "private": true
}

Find the exact location

Paste the document into the JSON Validator. It reports the parser message and, when the runtime provides a position, the corresponding line and column. Your data stays in the browser.

Frequently asked questions

Are trailing commas allowed in JSON?

No. Standard JSON does not permit a trailing comma after the last object property or array item.

Why does JavaScript accept a trailing comma?

JavaScript object and array literals follow JavaScript syntax, while JSON follows a smaller and stricter data format.

Related JSON guides